This route is sometimes known as the Sawtooth Ridge Epic.
This ride has it all: old growth forest, pristine lakes, great views, very narrow trail, some climbing challenge, a stretch of flowy downhill and to finish a section of steeper downhill with many switchbacks. Perhaps the one thing missing is an actual peak--despite the name, the route does not go to the top of Osborne Mountain. If you want panoramic views, do the three mile side hike up High Rock that's described below. This is a great ride, more people should check it out.
The ride difficulty is in the same class as, but a bit higher than the Lower Dungeness-Gold Creek trail loop. There are some tough climbs, and there are long, long stretches of very narrow trail with side slope exposure.
The adventure consists of a 11 mile approach on forest roads, and a 12 mile return that's mostly singletrack with a short road climb in the middle. The ride can also be done as a point-to-point shuttle. The shuttle makes it a 12 mile ride that still has 2500 feet of climbing.
The route does not go above 5,000 feet, but does use trail sections on north-facing slopes in deep forest. Do not expect snow to melt off early in the season.
Trail is generally in very good shape, with very narrow singletrack, especially considering much of the route is open to motorcycles.
Copper Creek Inn, about 2 miles east on SR-706 from the Skate Creek Rd turnoff, is a good choice that serves both burgers and real entrees. No beer on tap, but an OK selection of bottles.
In Ashford, the Basecamp Bar & Grill right behind Whittaker Mountaineering has excellent pizza, burgers, good beer on tap, and a great atmosphere. Seating is outdoor with a covered area, and it might only be open in summer.
There are a number of dinner options in Elbe, including the rail car restaurant and the burger shack across the street from it.
6-29-13 We had no trouble finding 4 camp sites at Big Creek CG on Saturday morning. This CG doesn't see much use. Nice shady spot.